8u20 review request: RT-36341 - error loading image without extension on retina Mac

[Jim Graham]

webrev: http://cr.openjdk.java.net/~flar/RT-36341/webrev.00/
Jira: https://javafx-jira.kenai.com/browse/RT-36341

It will be hard to verify the test because webrev mangled the patch file 
on the test file, but any image file renamed to the appropriate file 
name should work as indicated in the comments in the Jira...

			...jim